Transition mutation is due to replacement of

Question

Transition mutation is due to replacement of (A) GC by TA (B) AT by CG (C) CG by GC (D) AT by GC

Tardigrade Admin · Accepted Answer

Substitution (Replacement): In substitution a nitrogen base is changed with another base. It is of two types—transition and tranversion
1. Transition : Purine is replaced by purine

(A G)

while pyrimidine is replaced by pyrimidine

(C T, C U)

,
2. Transversion : Purine is replaced by pyrimidine

(A \to C)

while pyrimidine is replaced by purine

(C \to A), e . g . : SC A (G A G \to G U G) .

A classical example of point mutation is a change of single base pair in the gene for beta globin chain that results in the change of amino acid residue glutamate to valine. It results into a diseased condition called as sickle cell anemia.

Q. Transition mutation is due to replacement of

$GC$ by $T A$

$A T$ by $CG$

$CG$ by $GC$

$A T$ by $GC$